Thread: Parallel Query Processing

On Wed, Mar 25, 2009 at 2:24 PM, aravind chandu <avin_friends@yahoo.com> wrote:
> Hello,
>
>             I have a few questions related to the parallel query
> processing.Can you guys tell me how to implement parallel query processing
> in postgresql database.

Do you mean one query being parallelized, or multiple queries running at once?

PostgreSQL provides no capability to parallelize one query into
multiple processes.

Multiple Queries run in parallel automatically

You could run parallel queries across multiple servers using pgpool-II.

~Cory Coager

aravind chandu said the following on 03/25/2009 04:24 PM:

Hello,

            I have a few questions related to the parallel query processing.Can you guys tell me how to implement parallel query processing in postgresql database.

Thanks,
Avin.

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On Wed, 2009-03-25 at 15:52 -0600, Scott Marlowe wrote:
> On Wed, Mar 25, 2009 at 2:24 PM, aravind chandu <avin_friends@yahoo.com> wrote:
> > Hello,
> >
> >             I have a few questions related to the parallel query
> > processing.Can you guys tell me how to implement parallel query processing
> > in postgresql database.
>
> Do you mean one query being parallelized, or multiple queries running at once?
>
> PostgreSQL provides no capability to parallelize one query into
> multiple processes.

I have a tool that will allow you to manually parallelize a query (and
get the right answer). That is useful for certain larger queries. I'll
be publishing that a bit more visibly in next few months.

--
 Simon Riggs           www.2ndQuadrant.com
 PostgreSQL Training, Services and Support

On Thu, Mar 26, 2009 at 05:04:29PM +0000, Simon Riggs wrote:
>
> On Wed, 2009-03-25 at 15:52 -0600, Scott Marlowe wrote:
> > On Wed, Mar 25, 2009 at 2:24 PM, aravind chandu <avin_friends@yahoo.com> wrote:
> > > Hello,
> > >
> > > I have a few questions related to the parallel query
> > > processing.Can you guys tell me how to implement parallel query
> > > processing in postgresql database.
> >
> > Do you mean one query being parallelized, or multiple queries
> > running at once?
> >
> > PostgreSQL provides no capability to parallelize one query into
> > multiple processes.
>
> I have a tool that will allow you to manually parallelize a query
> (and get the right answer). That is useful for certain larger
> queries. I'll be publishing that a bit more visibly in next few
> months.

Is this snapshot cloning?  If so, thanks very much for publishing it! :)

If not, I'm really curious as to what it is :)

On the subject of snapshot cloning, I can see, at least in broad brush
strokes, how this would work for read queries, but I'm curious how (or
if) it could work for writes like, for example, updates of many
partitions at once.  Could it?

Cheers,
David.
--
David Fetter <david@fetter.org> http://fetter.org/
Phone: +1 415 235 3778  AIM: dfetter666  Yahoo!: dfetter
Skype: davidfetter      XMPP: david.fetter@gmail.com

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On Thu, 2009-03-26 at 10:12 -0700, David Fetter wrote:
> On Thu, Mar 26, 2009 at 05:04:29PM +0000, Simon Riggs wrote:
> >
> > On Wed, 2009-03-25 at 15:52 -0600, Scott Marlowe wrote:
> > > On Wed, Mar 25, 2009 at 2:24 PM, aravind chandu <avin_friends@yahoo.com> wrote:
> > > > Hello,
> > > >
> > > > I have a few questions related to the parallel query
> > > > processing.Can you guys tell me how to implement parallel query
> > > > processing in postgresql database.
> > >

> > > PostgreSQL provides no capability to parallelize one query into
> > > multiple processes.
> >
> > I have a tool that will allow you to manually parallelize a query
> > (and get the right answer). That is useful for certain larger
> > queries. I'll be publishing that a bit more visibly in next few
> > months.
>
> Is this snapshot cloning?

Basically, yes.

> On the subject of snapshot cloning, I can see, at least in broad brush
> strokes, how this would work for read queries, but I'm curious how (or
> if) it could work for writes like, for example, updates of many
> partitions at once.  Could it?

Yes, think so, since most writes involve first reading the data.

--
 Simon Riggs           www.2ndQuadrant.com
 PostgreSQL Training, Services and Support